middleware_test.js

'use strict'

/* global describe, beforeEach, it, afterEach */
/* eslint-disable no-unused-expressions */

// Assertions and Stubbing
const chai = require('chai')
const sinon = require('sinon')
chai.use(require('sinon-chai'))

const expect = chai.expect

// Hubot classes
const Robot = require('../src/robot')
const TextMessage = require('../src/message').TextMessage
const Response = require('../src/response')
const Middleware = require('../src/middleware')

// mock `hubot-mock-adapter` module from fixture
const mockery = require('mockery')

describe('Middleware', function () {
  describe('Unit Tests', function () {
    beforeEach(function () {
      // Stub out event emitting
      this.robot = { emit: sinon.spy() }

      this.middleware = new Middleware(this.robot)
    })

    describe('#execute', function () {
      it('executes synchronous middleware', function (testDone) {
        const testMiddleware = sinon.spy((context, next, done) => {
          next(done)
        })

        this.middleware.register(testMiddleware)

        const middlewareFinished = function () {
          expect(testMiddleware).to.have.been.called
          testDone()
        }

        this.middleware.execute(
          {},
          (_, done) => done(),
          middlewareFinished
        )
      })

      it('executes asynchronous middleware', function (testDone) {
        const testMiddleware = sinon.spy((context, next, done) =>
          // Yield to the event loop
          process.nextTick(() => next(done))
        )

        this.middleware.register(testMiddleware)

        const middlewareFinished = function (context, done) {
          expect(testMiddleware).to.have.been.called
          testDone()
        }

        this.middleware.execute(
          {},
          (_, done) => done(),
          middlewareFinished
        )
      })

      it('passes the correct arguments to each middleware', function (testDone) {
        const testContext = {}
        const testMiddleware = (context, next, done) =>
          // Break out of middleware error handling so assertion errors are
          // more visible
          process.nextTick(function () {
            // Check that variables were passed correctly
            expect(context).to.equal(testContext)
            next(done)
          })

        this.middleware.register(testMiddleware)

        this.middleware.execute(
          testContext,
          (_, done) => done(),
          () => testDone())
      })

      it('executes all registered middleware in definition order', function (testDone) {
        const middlewareExecution = []

        const testMiddlewareA = (context, next, done) => {
          middlewareExecution.push('A')
          next(done)
        }

        const testMiddlewareB = function (context, next, done) {
          middlewareExecution.push('B')
          next(done)
        }

        this.middleware.register(testMiddlewareA)
        this.middleware.register(testMiddlewareB)

        const middlewareFinished = function () {
          expect(middlewareExecution).to.deep.equal(['A', 'B'])
          testDone()
        }

        this.middleware.execute(
          {},
          (_, done) => done(),
          middlewareFinished
        )
      })

      it('executes the next callback after the function returns when there is no middleware', function (testDone) {
        let finished = false
        this.middleware.execute(
          {},
          function () {
            expect(finished).to.be.ok
            testDone()
          },
          function () {}
        )
        finished = true
      })

      it('always executes middleware after the function returns', function (testDone) {
        let finished = false

        this.middleware.register(function (context, next, done) {
          expect(finished).to.be.ok
          testDone()
        })

        this.middleware.execute({}, function () {}, function () {})
        finished = true
      })

      it('creates a default "done" function', function (testDone) {
        let finished = false

        this.middleware.register(function (context, next, done) {
          expect(finished).to.be.ok
          testDone()
        })

        // we're testing the lack of a third argument here.
        this.middleware.execute({}, function () {})
        finished = true
      })

      it('does the right thing with done callbacks', function (testDone) {
        // we want to ensure that the 'done' callbacks are nested correctly
        // (executed in reverse order of definition)
        const execution = []

        const testMiddlewareA = function (context, next, done) {
          execution.push('middlewareA')
          next(function () {
            execution.push('doneA')
            done()
          })
        }

        const testMiddlewareB = function (context, next, done) {
          execution.push('middlewareB')
          next(function () {
            execution.push('doneB')
            done()
          })
        }

        this.middleware.register(testMiddlewareA)
        this.middleware.register(testMiddlewareB)

        const allDone = function () {
          expect(execution).to.deep.equal(['middlewareA', 'middlewareB', 'doneB', 'doneA'])
          testDone()
        }

        this.middleware.execute(
          {},
          // Short circuit at the bottom of the middleware stack
          (_, done) => done(),
          allDone
        )
      })

      it('defaults to the latest done callback if none is provided', function (testDone) {
        // we want to ensure that the 'done' callbacks are nested correctly
        // (executed in reverse order of definition)
        const execution = []

        const testMiddlewareA = function (context, next, done) {
          execution.push('middlewareA')
          next(function () {
            execution.push('doneA')
            done()
          })
        }

        const testMiddlewareB = function (context, next, done) {
          execution.push('middlewareB')
          next()
        }

        this.middleware.register(testMiddlewareA)
        this.middleware.register(testMiddlewareB)

        const allDone = function () {
          expect(execution).to.deep.equal(['middlewareA', 'middlewareB', 'doneA'])
          testDone()
        }

        this.middleware.execute(
          {},
          // Short circuit at the bottom of the middleware stack
          (_, done) => done(),
          allDone
        )
      })

      describe('error handling', function () {
        it('does not execute subsequent middleware after the error is thrown', function (testDone) {
          const middlewareExecution = []

          const testMiddlewareA = function (context, next, done) {
            middlewareExecution.push('A')
            next(done)
          }

          const testMiddlewareB = function (context, next, done) {
            middlewareExecution.push('B')
            throw new Error()
          }

          const testMiddlewareC = function (context, next, done) {
            middlewareExecution.push('C')
            next(done)
          }

          this.middleware.register(testMiddlewareA)
          this.middleware.register(testMiddlewareB)
          this.middleware.register(testMiddlewareC)

          const middlewareFinished = sinon.spy()
          const middlewareFailed = () => {
            expect(middlewareFinished).to.not.have.been.called
            expect(middlewareExecution).to.deep.equal(['A', 'B'])
            testDone()
          }

          this.middleware.execute(
            {},
            middlewareFinished,
            middlewareFailed
          )
        })

        it('emits an error event', function (testDone) {
          const testResponse = {}
          const theError = new Error()

          const testMiddleware = function (context, next, done) {
            throw theError
          }

          this.middleware.register(testMiddleware)

          this.robot.emit = sinon.spy(function (name, err, response) {
            expect(name).to.equal('error')
            expect(err).to.equal(theError)
            expect(response).to.equal(testResponse)
          })

          const middlewareFinished = sinon.spy()
          const middlewareFailed = () => {
            expect(this.robot.emit).to.have.been.called
            testDone()
          }

          this.middleware.execute(
            { response: testResponse },
            middlewareFinished,
            middlewareFailed
          )
        })

        it('unwinds the middleware stack (calling all done functions)', function (testDone) {
          let extraDoneFunc = null

          const testMiddlewareA = function (context, next, done) {
            // Goal: make sure that the middleware stack is unwound correctly
            extraDoneFunc = sinon.spy(done)
            next(extraDoneFunc)
          }

          const testMiddlewareB = function (context, next, done) {
            throw new Error()
          }

          this.middleware.register(testMiddlewareA)
          this.middleware.register(testMiddlewareB)

          const middlewareFinished = sinon.spy()
          const middlewareFailed = function () {
            // Sanity check that the error was actually thrown
            expect(middlewareFinished).to.not.have.been.called

            expect(extraDoneFunc).to.have.been.called
            testDone()
          }

          this.middleware.execute(
            {},
            middlewareFinished,
            middlewareFailed
          )
        })
      })
    })

    describe('#register', function () {
      it('adds to the list of middleware', function () {
        const testMiddleware = function (context, next, done) {}

        this.middleware.register(testMiddleware)

        expect(this.middleware.stack).to.include(testMiddleware)
      })

      it('validates the arity of middleware', function () {
        const testMiddleware = function (context, next, done, extra) {}

        expect(() => this.middleware.register(testMiddleware)).to.throw(/Incorrect number of arguments/)
      })
    })
  })

  // Per the documentation in docs/scripting.md
  // Any new fields that are exposed to middleware should be explicitly
  // tested for.
  describe('Public Middleware APIs', function () {
    beforeEach(async function () {
      mockery.enable({
        warnOnReplace: false,
        warnOnUnregistered: false
      })
      mockery.registerMock('hubot-mock-adapter', require('./fixtures/mock-adapter.js'))
      process.env.EXPRESS_PORT = 0
      this.robot = new Robot('mock-adapter', true, 'TestHubot')
      await this.robot.loadAdapter()
      this.robot.run

      // Re-throw AssertionErrors for clearer test failures
      this.robot.on('error', function (name, err, response) {
        if (__guard__(err != null ? err.constructor : undefined, x => x.name) === 'AssertionError') {
          process.nextTick(function () {
            throw err
          })
        }
      })

      this.user = this.robot.brain.userForId('1', {
        name: 'hubottester',
        room: '#mocha'
      })

      // Dummy middleware
      this.middleware = sinon.spy((context, next, done) => next(done))

      this.testMessage = new TextMessage(this.user, 'message123')
      this.robot.hear(/^message123$/, function (response) {})
      this.testListener = this.robot.listeners[0]
    })

    afterEach(function () {
      mockery.disable()
      this.robot.shutdown()
    })

    describe('listener middleware context', function () {
      beforeEach(function () {
        this.robot.listenerMiddleware((context, next, done) => {
          this.middleware(context, next, done)
        })
      })

      describe('listener', function () {
        it('is the listener object that matched', function (testDone) {
          this.robot.receive(this.testMessage, () => {
            expect(this.middleware).to.have.been.calledWithMatch(
              sinon.match.has('listener',
                sinon.match.same(this.testListener)), // context
              sinon.match.any, // next
              sinon.match.any // done
            )
            testDone()
          })
        })

        it('has options.id (metadata)', function (testDone) {
          this.robot.receive(this.testMessage, () => {
            expect(this.middleware).to.have.been.calledWithMatch(
              sinon.match.has('listener',
                sinon.match.has('options',
                  sinon.match.has('id'))), // context
              sinon.match.any, // next
              sinon.match.any // done
            )
            testDone()
          })
        })
      })

      describe('response', () =>
        it('is a Response that wraps the message', function (testDone) {
          this.robot.receive(this.testMessage, () => {
            expect(this.middleware).to.have.been.calledWithMatch(
              sinon.match.has('response',
                sinon.match.instanceOf(Response).and(
                  sinon.match.has('message',
                    sinon.match.same(this.testMessage)))), // context
              sinon.match.any, // next
              sinon.match.any // done
            )
            testDone()
          })
        })
      )
    })

    describe('receive middleware context', function () {
      beforeEach(function () {
        this.robot.receiveMiddleware((context, next, done) => {
          this.middleware(context, next, done)
        })
      })

      describe('response', () =>
        it('is a match-less Response object', function (testDone) {
          this.robot.receive(this.testMessage, () => {
            expect(this.middleware).to.have.been.calledWithMatch(
              sinon.match.has('response',
                sinon.match.instanceOf(Response).and(
                  sinon.match.has('message',
                    sinon.match.same(this.testMessage)))), // context
              sinon.match.any, // next
              sinon.match.any // done
            )
            testDone()
          })
        })
      )
    })

    describe('next', function () {
      beforeEach(function () {
        this.robot.listenerMiddleware((context, next, done) => {
          this.middleware(context, next, done)
        })
      })

      it('is a function with arity one', function (testDone) {
        this.robot.receive(this.testMessage, () => {
          expect(this.middleware).to.have.been.calledWithMatch(
            sinon.match.any, // context
            sinon.match.func.and(
              sinon.match.has('length',
                sinon.match(1))), // next
            sinon.match.any // done
          )
          testDone()
        })
      })
    })

    describe('done', function () {
      beforeEach(function () {
        this.robot.listenerMiddleware((context, next, done) => {
          this.middleware(context, next, done)
        })
      })

      it('is a function with arity zero', function (testDone) {
        this.robot.receive(this.testMessage, () => {
          expect(this.middleware).to.have.been.calledWithMatch(
            sinon.match.any, // context
            sinon.match.any, // next
            sinon.match.func.and(
              sinon.match.has('length',
                sinon.match(0))) // done
          )
          testDone()
        })
      })
    })
  })
})

function __guard__ (value, transform) {
  (typeof value !== 'undefined' && value !== null) ? transform(value) : undefined
}